Ryan Mathews is a bit of a tease. He looks like he could be a top-five NFL running back, but injury issues have prevented that from happening.

Mathews made a successful, speedy return from a broken clavicle to play in last week's game for the San Diego Chargers, but then another old problem popped up: fumbling. He has done it 11 times in just 23 career starts. Last week, it happened near the goal line.

"I am very concerned, and it has to stop," Smith told Kevin Acee of U-T San Diego. "I believe you can improve in ball security. And no one works any harder in trying to get better than Ryan. However, if it continues he will play less."

"Extremely talented players like Ryan get multiple opportunities to improve," Smith continued. "What happens to fumblers is, first, they play less. Second, if it continues while they're playing on a limited basis, then you don't play for a while and you get to sit and think about it.

"Third, when you get the call to go back on the field and the fumbling continues, then you will be somebody else's fumbler."

Harsh. The process already has started. Turner indicated Monday that Mathews might come out of the game when the Chargers are closer to the goal line. That's bad news for Mathews' fantasy owners, and worse news for him.